ON THE DOCKET: Edie Windsor’s fight for equal benefits after the death of her same-sex partner Thea Spyer (left) reaches the Supreme Court today.AP

Edie Windsor was forced to pay more than $363,000 in estate taxes after her same-sex spouse, Thea Spyer, died in 2009.

So Windsor, an 83-year-old New Yorker, decided to take on the government to right the wrong.

“If Thea was Theo, I would not have had to pay that,” she said.

“It’s heartbreaking. It’s just a terrible injustice, and I don’t expect that from my country.”

Windsor’s case challenging the federal Defense of Marriage Act will be heard today by the US Supreme Court, a day after justices heard arguments on California’s voter-approved ban on same-sex marriage.

The 1996 federal law denies benefits to married same-sex spouses.

The Obama administration won’t defend the law, so the House of Representatives’ Republican leadership will.

The court could decide that the House does not have standing to do that. If so, the Manhattan woman would get her money back, because a lower court ruled for her.

But it could still deny benefits to same-sex married couples in nine states and the District of Columbia, according to Windsor’s attorney, Roberta Kaplan.

Windsor said she wore a diamond brooch, not an engagement ring, to signal her 42-year relationship with Spyer.

“Our choice not to wear traditional engagement rings was just one of many ways in which Thea and I had to mold our lives to make our relationship invisible,” Windsor said in an affidavit.